I'm trying to Parse a String with Boost::Spirit, but i just cannot get it to work. I have no experience with Boost::Spirit since today.
The string is composed of commands separated by an ';'. The commands are
"INC someInteger"
"BOMB firstInteger secondInteger"
"MOVE firstInteger secondInteger thirdInteger"
"MSG someString"
"WAIT"
I Managed to get this far:
#include <boost/spirit/include/qi.hpp>
#include <boost/phoenix/phoenix.hpp>
using namespace boost::spirit;
int main() {
std::string testInput = "MOVE 1 2 43;BOMB 0 3;INC 6;MOVE 2 3 99;MOVE 1 2 6";
typedef std::string::iterator iter;
using boost::phoenix::ref;
iter start = testInput.begin();
std::vector<int> IncCommands;
std::vector<std::pair<int, int>> BombCommands;
std::vector<std::tuple<int, int, int>> MoveCommands;
qi::rule<iter, std::vector<int>(), ascii::space_type> nextIncrease = ("INC " >> qi::int_);
//qi::rule<iter, std::vector<std::pair<int, int>>(), ascii::space_type> nextBomb = ("BOMB " >> qi::int_ >> qi::int_);
//qi::rule<iter, std::vector<int>(), ascii::space_type> nextMove = ("MOVE " >> qi::int_ >> qi::int_ >> qi::int_);
//qi::rule<iter, std::string, ascii::space_type> nextAction = (nextMove | nextBomb | nextIncrease) % ';';
bool match = qi::phrase_parse(
start,
testInput.end(),
nextIncrease,
ascii::space,
IncCommands
);
return 0;
}
The Problems that i have now:
I don't know how i can extract more than 1 integer
I don't know how i can merge everything into a proper grammar so that everything is parsed into several vectors.
I didn't consider MSG and WAIT yet.
I'd suggest starting out with the desired AST as always.
Spirit works well with static polymorphism, so I'd use a variant to represent commands:
namespace AST {
namespace Cmd {
struct Move { int x,y,z; };
struct Bomb { int x,y; };
struct Inc { int amount; };
struct Msg { std::string text; };
struct Wait {};
}
using Command = boost::variant<Cmd::Move, Cmd::Bomb, Cmd::Inc, Cmd::Msg, Cmd::Wait>;
using Commands = std::vector<Command>;
}
Now, write the most straight-forward grammar to match it:
template <typename It>
struct ScriptGrammar : qi::grammar<It, AST::Commands()>
{
ScriptGrammar() : ScriptGrammar::base_type(start) {
using namespace qi;
start = skip(space) [ script ];
script = command % ";";
command = move|bomb|inc|msg|wait;
move = "MOVE" >> int_ >> int_ >> int_;
bomb = "BOMB" >> int_ >> int_;
inc = "INC" >> int_;
msg = "MSG" >> text;
wait = "WAIT" >> qi::attr(AST::Cmd::Wait{});
text = +~char_(";");
BOOST_SPIRIT_DEBUG_NODES((start)(script)(command)(move)(bomb)(inc)(msg)(wait)(text))
}
private:
using Skipper = qi::space_type;
qi::rule<It, AST::Commands(), Skipper> script;
qi::rule<It, AST::Command(), Skipper> command;
qi::rule<It, AST::Cmd::Move(), Skipper> move;
qi::rule<It, AST::Cmd::Bomb(), Skipper> bomb;
qi::rule<It, AST::Cmd::Inc(), Skipper> inc;
qi::rule<It, AST::Cmd::Msg(), Skipper> msg;
qi::rule<It, AST::Cmd::Wait(), Skipper> wait;
// lexeme
qi::rule<It, AST::Commands()> start;
qi::rule<It, std::string()> text;
};
Add in some glue for debug (Fusion adaptation and output streaming), and we have a working sample:
#define BOOST_SPIRIT_DEBUG
#include <iostream>
#include <vector>
#include <string>
#include <iterator>
#include <iomanip>
#include <boost/spirit/include/qi.hpp>
#include <boost/fusion/include/adapt_struct.hpp>
#include <boost/phoenix/phoenix.hpp>
namespace AST {
namespace Cmd {
struct Move { int x,y,z; };
struct Bomb { int x,y; };
struct Inc { int amount; };
struct Msg { std::string text; };
struct Wait {};
}
using Command = boost::variant<Cmd::Move, Cmd::Bomb, Cmd::Inc, Cmd::Msg, Cmd::Wait>;
using Commands = std::vector<Command>;
}
BOOST_FUSION_ADAPT_STRUCT(AST::Cmd::Move, x,y,z)
BOOST_FUSION_ADAPT_STRUCT(AST::Cmd::Bomb, x,y)
BOOST_FUSION_ADAPT_STRUCT(AST::Cmd::Inc, amount)
BOOST_FUSION_ADAPT_STRUCT(AST::Cmd::Msg, text)
BOOST_FUSION_ADAPT_STRUCT(AST::Cmd::Wait)
namespace AST { namespace Cmd { // For demo/debug
std::ostream& operator<<(std::ostream& os, Move const& cmd) { return os << "MOVE " << boost::fusion::as_vector(cmd); }
std::ostream& operator<<(std::ostream& os, Bomb const& cmd) { return os << "BOMB " << boost::fusion::as_vector(cmd); }
std::ostream& operator<<(std::ostream& os, Inc const& cmd) { return os << "INC " << boost::fusion::as_vector(cmd); }
std::ostream& operator<<(std::ostream& os, Msg const& cmd) { return os << "MSG " << boost::fusion::as_vector(cmd); }
std::ostream& operator<<(std::ostream& os, Wait const& cmd) { return os << "WAIT " << boost::fusion::as_vector(cmd); }
} }
namespace qi = boost::spirit::qi;
template <typename It>
struct ScriptGrammar : qi::grammar<It, AST::Commands()>
{
ScriptGrammar() : ScriptGrammar::base_type(start) {
using namespace qi;
start = skip(space) [ script ];
script = command % ";";
command = move|bomb|inc|msg|wait;
move = "MOVE" >> int_ >> int_ >> int_;
bomb = "BOMB" >> int_ >> int_;
inc = "INC" >> int_;
msg = "MSG" >> text;
wait = "WAIT" >> qi::attr(AST::Cmd::Wait{});
text = +~char_(";");
BOOST_SPIRIT_DEBUG_NODES((start)(script)(command)(move)(bomb)(inc)(msg)(wait)(text))
}
private:
using Skipper = qi::space_type;
qi::rule<It, AST::Commands(), Skipper> script;
qi::rule<It, AST::Command(), Skipper> command;
qi::rule<It, AST::Cmd::Move(), Skipper> move;
qi::rule<It, AST::Cmd::Bomb(), Skipper> bomb;
qi::rule<It, AST::Cmd::Inc(), Skipper> inc;
qi::rule<It, AST::Cmd::Msg(), Skipper> msg;
qi::rule<It, AST::Cmd::Wait(), Skipper> wait;
// lexeme
qi::rule<It, AST::Commands()> start;
qi::rule<It, std::string()> text;
};
int main() {
std::string const testInput = "MOVE 1 2 43;BOMB 0 3;INC 6;MOVE 2 3 99;MSG MOVE ZIG;WAIT;MSG FOR GREAT JUSTICE!;MOVE 1 2 6";
typedef std::string::const_iterator iter;
iter start = testInput.begin(), end = testInput.end();
AST::Commands script;
bool match = qi::parse(start, testInput.end(), ScriptGrammar<iter>(), script);
if (match) {
std::cout << "Parsed " << script.size() << " commands\n";
std::copy(script.begin(), script.end(), std::ostream_iterator<AST::Command>(std::cout, ";"));
} else {
std::cout << "Parse failed\n";
}
if (start != end)
std::cout << "Remaining unparsed input: '" << std::string(start, end) << "'\n";
}
Which prints:
Parsed 8 commands
MOVE (1 2 43);BOMB (0 3);INC (6);MOVE (2 3 99);MSG (MOVE ZIG);WAIT ();MSG (FOR GREAT JUSTICE!);MOVE (1 2 6);
And optionally the BOOST_SPIRIT_DEBUG output:
<start>
<try>MOVE 1 2 43;BOMB 0 3</try>
<script>
<try>MOVE 1 2 43;BOMB 0 3</try>
<command>
<try>MOVE 1 2 43;BOMB 0 3</try>
<move>
<try>MOVE 1 2 43;BOMB 0 3</try>
<success>;BOMB 0 3;INC 6;MOVE</success>
<attributes>[[1, 2, 43]]</attributes>
</move>
<success>;BOMB 0 3;INC 6;MOVE</success>
<attributes>[[1, 2, 43]]</attributes>
</command>
<command>
<try>BOMB 0 3;INC 6;MOVE </try>
<move>
<try>BOMB 0 3;INC 6;MOVE </try>
<fail/>
</move>
<bomb>
<try>BOMB 0 3;INC 6;MOVE </try>
<success>;INC 6;MOVE 2 3 99;M</success>
<attributes>[[0, 3]]</attributes>
</bomb>
<success>;INC 6;MOVE 2 3 99;M</success>
<attributes>[[0, 3]]</attributes>
</command>
<command>
<try>INC 6;MOVE 2 3 99;MS</try>
<move>
<try>INC 6;MOVE 2 3 99;MS</try>
<fail/>
</move>
<bomb>
<try>INC 6;MOVE 2 3 99;MS</try>
<fail/>
</bomb>
<inc>
<try>INC 6;MOVE 2 3 99;MS</try>
<success>;MOVE 2 3 99;MSG MOV</success>
<attributes>[[6]]</attributes>
</inc>
<success>;MOVE 2 3 99;MSG MOV</success>
<attributes>[[6]]</attributes>
</command>
<command>
<try>MOVE 2 3 99;MSG MOVE</try>
<move>
<try>MOVE 2 3 99;MSG MOVE</try>
<success>;MSG MOVE ZIG;WAIT;M</success>
<attributes>[[2, 3, 99]]</attributes>
</move>
<success>;MSG MOVE ZIG;WAIT;M</success>
<attributes>[[2, 3, 99]]</attributes>
</command>
<command>
<try>MSG MOVE ZIG;WAIT;MS</try>
<move>
<try>MSG MOVE ZIG;WAIT;MS</try>
<fail/>
</move>
<bomb>
<try>MSG MOVE ZIG;WAIT;MS</try>
<fail/>
</bomb>
<inc>
<try>MSG MOVE ZIG;WAIT;MS</try>
<fail/>
</inc>
<msg>
<try>MSG MOVE ZIG;WAIT;MS</try>
<text>
<try>MOVE ZIG;WAIT;MSG FO</try>
<success>;WAIT;MSG FOR GREAT </success>
<attributes>[[M, O, V, E, , Z, I, G]]</attributes>
</text>
<success>;WAIT;MSG FOR GREAT </success>
<attributes>[[[M, O, V, E, , Z, I, G]]]</attributes>
</msg>
<success>;WAIT;MSG FOR GREAT </success>
<attributes>[[[M, O, V, E, , Z, I, G]]]</attributes>
</command>
<command>
<try>WAIT;MSG FOR GREAT J</try>
<move>
<try>WAIT;MSG FOR GREAT J</try>
<fail/>
</move>
<bomb>
<try>WAIT;MSG FOR GREAT J</try>
<fail/>
</bomb>
<inc>
<try>WAIT;MSG FOR GREAT J</try>
<fail/>
</inc>
<msg>
<try>WAIT;MSG FOR GREAT J</try>
<fail/>
</msg>
<wait>
<try>WAIT;MSG FOR GREAT J</try>
<success>;MSG FOR GREAT JUSTI</success>
<attributes>[[]]</attributes>
</wait>
<success>;MSG FOR GREAT JUSTI</success>
<attributes>[[]]</attributes>
</command>
<command>
<try>MSG FOR GREAT JUSTIC</try>
<move>
<try>MSG FOR GREAT JUSTIC</try>
<fail/>
</move>
<bomb>
<try>MSG FOR GREAT JUSTIC</try>
<fail/>
</bomb>
<inc>
<try>MSG FOR GREAT JUSTIC</try>
<fail/>
</inc>
<msg>
<try>MSG FOR GREAT JUSTIC</try>
<text>
<try>FOR GREAT JUSTICE!;M</try>
<success>;MOVE 1 2 6</success>
<attributes>[[F, O, R, , G, R, E, A, T, , J, U, S, T, I, C, E, !]]</attributes>
</text>
<success>;MOVE 1 2 6</success>
<attributes>[[[F, O, R, , G, R, E, A, T, , J, U, S, T, I, C, E, !]]]</attributes>
</msg>
<success>;MOVE 1 2 6</success>
<attributes>[[[F, O, R, , G, R, E, A, T, , J, U, S, T, I, C, E, !]]]</attributes>
</command>
<command>
<try>MOVE 1 2 6</try>
<move>
<try>MOVE 1 2 6</try>
<success></success>
<attributes>[[1, 2, 6]]</attributes>
</move>
<success></success>
<attributes>[[1, 2, 6]]</attributes>
</command>
<success></success>
<attributes>[[[1, 2, 43], [0, 3], [6], [2, 3, 99], [[M, O, V, E, , Z, I, G]], [], [[F, O, R, , G, R, E, A, T, , J, U, S, T, I, C, E, !]], [1, 2, 6]]]</attributes>
</script>
<success></success>
<attributes>[[[1, 2, 43], [0, 3], [6], [2, 3, 99], [[M, O, V, E, , Z, I, G]], [], [[F, O, R, , G, R, E, A, T, , J, U, S, T, I, C, E, !]], [1, 2, 6]]]</attributes>
</start>